Boto3 (Lib for s3 media backend) is not included in Dockerfiles

[MaxRink]

As it is right now boto3 isnt included in the dockerfile, which makes using S3 as filebackend impossible without building your own image.
Given the fact that S3 would be very usefull in the container ( as that makes scaling to multiple instances easier), is there any interest in including it in the image?

[cimnine]

I think that could actually e a good idea.

[tobiasge]

We should include this. Django-storages is not usable without a backend. In the setup.cfg of django-storages I found these requirements:

azure =
    azure-storage-blob >=1.3.1,<12.0.0
boto3 =
    boto3 >= 1.4.4
dropbox =
    dropbox >= 7.2.1
google =
    google-cloud-storage >= 1.15.0
libcloud =
    apache-libcloud
sftp =
    paramiko

I think we should include the backends for the most common service. My suggestion would be: boto3, azure-storage-blob and google-cloud-storage.

[cimnine]

Why not just all of them?

[tobiasge]

I just thought we could keep the images smaller, but we can also add all. I think the best way would be to use the extra requirements. That we don't have to keep track of the versions:
django-storages[azure,boto3,dropbox,google,libcloud,sftp]==1.11.1 in our requirements-container.txt

[tobiasge]

Pull request for this: #421